The present invention relates to a dump truck end gate locking system.
A dump truck has a cargo box with a pivotally mounted end gate. The end gate pivots about a substantially horizontal pivot axis defined by pivot pins positioned on opposed sides adjacent a top peripheral edge of the end gate. Locks are provided to maintain the end gate in a closed position during transport. Problems arise if an operator of the dump truck forgets to either lock the end gate prior to loading or unlock the end gate prior to tilting the cargo box. If the operator loads without locking the end gate, material accumulated in the cargo box prevents the end gate from being placed in the locking position. This requires material to be manually removed from the cargo box adjacent the end gate in order to close and lock the end gate. If the operator tilts the cargo box without having unlocked the end gate, the weight of material against the end gate causes material to spill from the cargo box in an uncontrolled manner when the end gate is eventually opened.
What is required is a dump truck end gate locking system which will reduce or eliminate these problems from occurring.
According to the present invention there is provided a dump truck end gate locking system which includes a dump truck having a chassis and a cargo box pivotally mounted to the chassis for pivotal movement about a first substantially horizontal pivot axis between a substantially horizontal transport position and an inclined dumping position. The cargo box has an end gate pivotally mounted for pivotal movement about a second substantially horizontal pivot axis. A sensor is mounted to either the chassis or the cargo box for sensing when the cargo box is in the transport position. At least one movable locking member is mounted to the cargo box. The locking member has a locked position engaging the end gate and an unlocked position disengaged from the end gate. A drive mechanism is provided for the locking member coupled to the sensor. The drive mechanism moves the locking member to the locked position to secure the end gate when the sensor indicates the cargo box is in the transport position. The drive mechanism moves the locking member to the unlocked position to release the end gate when the sensor indicates the cargo box has moved from the transport position to assume a dumping position.
The dump truck end gate locking system, as described above, automatically locks and unlocks the end gate depending upon the position of the cargo box. This eliminates the possibility of human error. In the absence of mechanical failure the end gate will be locked when it should be locked and unlocked when it should be unlocked.
Once the teachings of the invention are understood, there are a number of different mechanisms that can be used to sense the position of the cargo box and to lock the end gate. A preferred embodiment of the dump truck end gate locking system will be hereinafter described.